Passive 3D requires two projectors to project the image for RH eye and LH eye separately. Two major passive 3D systems: a. Polarized system b. Band-pass system (Spetrum 3D system) When using polarized system, silver screen is required. If using Band-pass filter, conventional 2D screen can be used.

If bigger screen is required, user can use GeoBox to execute edge blending & passive 3D function to double screen size by 4x projectors--two projector edge blend for RH eye signal and another two projectors for LH eye signal. Bigger screen size can be achieved by cascaded more GeoBox. No synchronization issue will happen in passive 3D system. No limitation for the number of the proejctors and screen size. 

GeoBox has the ability to implement passive 3D on curved screen. Two projectors can be stacked perfectly on curved screen by Warp function in GeoBox.